Question

Solve systems of equations for y and x:

−5y + 8x = −18

5y + 2x = 58​

Answer 1

(4, 10)

General Formulas and Concepts:

Pre-Algebra

Order of Operations: BPEMDAS

1. Brackets
2. Parenthesis
3. Exponents
4. Multiplication
5. Division
6. Addition
7. Subtraction

• Left to Right

Equality Properties

• Multiplication Property of Equality
• Division Property of Equality
• Addition Property of Equality
• Subtraction Property of Equality

Algebra I

• Coordinates (x, y)
• Coefficients
• Solving systems of equations using substitution/elimination

Explanation:

Step 1: Define Systems

-5y + 8x = -18

5y + 2x = 58

Step 2: Solve for x

Elimination

1. Combine 2 equations: 10x = 40
2. [Division Property of Equality] Divide 10 on both sides: x = 4

Step 3: Solve for y

1. Substitute in x [Original equation]: -5y + 8(4) = -18
2. Multiply: -5y + 32 = -18
3. [Subtraction Property of Equality] Subtract 32 on both sides: -5y = -50
4. [Division Property of Equality] Divide -5 on both sides: y = 10